TW202015109A - Techniques and apparatus for anisotropic stress compensation in substrates using ion implantation - Google Patents

Abstract

A method may include providing a substrate, where the substrate includes a first main surface and a second main surface, opposite the first main surface. The second main surface may include a stress compensation layer. The method may include directing ions to the stress compensation layer in an ion implant procedure. The ion implant procedure may include exposing a first region of the stress compensation layer to a first implant process, wherein a second region of the stress compensation layer is not exposed to the first implant process.

Description

Technology and device using ion implantation for anisotropic stress compensation in substrate

The present embodiment relates to stress control in the substrate, and more specifically to stress compensation for reducing anisotropic planar stress in the substrate.

Components such as integrated circuits, memory components, and logic components can be fabricated on substrates such as silicon wafers through a combination of deposition processes, etching, ion implantation, annealing, and other processes. Generally, stress may be generated in the layer or patterned element formed on the surface of the substrate. The formation of some structures may require the deposition of multiple layers, which results in the formation of stress on the substrate. The layer stress can be expressed as a biaxial orientation (plane stress) along the main surface of the substrate. In some cases, the plane stress may be substantially parallel to the first major surface of the substrate and may be isotropic in nature, wherein the stress values oriented in different directions in the plane parallel to the first major surface are the same . Therefore, the isotropic biaxial stress may cause the well-known substrate bending phenomenon. As an example, compressive layer stress causes convex bending of the substrate, while tensile layer stress causes concave bending of the substrate.

In substrates with patterned features, such as vertical NAND (VNAND) memory elements, the formation of the elements may require the deposition of dozens of alternating layers, which also results in the accumulation of biaxial stress or planar stress. In some examples, slits may be formed within the layer stack, where the slits are aligned along a common direction. The slit can cause stress relief along the common direction, resulting in anisotropic planar stress, where the stress along the first direction in the substrate plane can have a greater value than the stress along the second direction in the substrate plane, and the first The two directions are perpendicular to the first direction. Such anisotropic plane stress can cause the amount of bending of the substrate in the first direction to be different from the amount of bending in the second direction.

With regard to these and other considerations, this embodiment is provided.

The content of the present invention is provided to introduce some concepts in a simplified form further described in the specific embodiments below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

In one embodiment, a method is provided. The method may include an operation of providing a substrate, wherein the substrate includes a first main surface and a second main surface opposite to the first main surface. The second major surface may include a stress compensation layer. The method may include the further operation of directing ions to the stress compensation layer during the ion implantation procedure. Therefore, the ion implantation procedure may include exposing the first region of the stress compensation layer to the first implantation process, wherein the second region of the stress compensation layer is not exposed to the first implantation process.

In another embodiment, a method may include the step of providing a patterned substrate, wherein the patterned substrate includes a first major surface and a second major surface opposite the first major surface. According to some embodiments, the patterned substrate further includes a feature component disposed on the first major surface, wherein the feature component generates a first stress state on the patterned substrate. The first stress state may include anisotropic stress in the first major surface. The method may further include the steps of depositing a stress compensation layer on the second major surface, and exposing the stress compensation to the ion implantation procedure. The implantation procedure may include scanning the first ion beam relative to the patterned substrate to implant a first dose of ions in the first area of the stress compensation layer. Therefore, the second region of the stress compensation layer is not exposed to the first dose of ions.

In another embodiment, an apparatus for stress control of a substrate is provided. The device may include a beam scanner that scans the ion beam relative to the substrate, where the substrate includes a stress control layer. The apparatus may include a user interface coupled to the beam scanner, and a controller coupled to the beam scanner and the user interface. The controller may include a processor and a memory unit coupled to the processor, where the memory unit includes a scan routine. The scanning routine can be operated on the processor to receive substrate stress information from the user interface and generate an implant pattern to control the beam scanner, where the implant pattern will generate anisotropic stress in the stress control layer.

The embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some embodiments are shown. The subject matter of the present invention can be embodied in many different forms and should not be interpreted as being limited to the embodiments set forth herein. Rather, these embodiments are provided to make the invention thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art. In the drawings, the same reference numerals always denote the same elements.

The embodiments described herein relate to techniques and devices for improving stress control in substrates, such as semiconductor wafers with patterned structures formed therein. This embodiment can be employed during component manufacturing to reduce stress generated during wafer processing (eg, component manufacturing). Various embodiments can be used to reduce the plane stress, especially the anisotropic plane stress.

In this embodiment, the ion beam generated in the ion implanter, especially the scanning spot beam, may be used. Various embodiments employ a novel ion implantation method to change the substrate curvature caused by stress in features formed on the substrate during element processing. In this embodiment, a novel pattern can be used to embed into the stress compensation layer, which is configured to generate compensation stress, wherein the compensation stress can be used to reduce the curvature in the substrate. Some embodiments may generate anisotropic planar stresses to compensate for pre-existing anisotropic planar stresses generated by structures on the substrate surface.

Referring now to FIG. 1A, a side cross-sectional view of the substrate 100 in the first case during processing of the substrate 100 is shown. At this stage, the feature component has been formed on the first major surface 106 of the substrate 100 as shown by the feature 104. As is known in the art, the features 104 may represent multiple layers, elements, semiconductor dies (wafers) manufactured in the surface area of the substrate 100. Although shown as discrete components, the features 104 may also generally be formed on the surface of the first major surface 106 in a continuous manner. In other words, the features 104 may be isolated from each other, connected to each other through a continuous layer, partially connected to each other, isolated from each other in the first direction, but not isolated from each other in the second direction. During the manufacture of the features 104, one or more layers (not separate) may be deposited on the substrate 100, at least one of which may exhibit intrinsic stress. For example, as more layers are deposited, the intrinsic stress within the layers may tend to increase, causing the substrate 100 to bend as shown.

As shown in the example shown in FIG. 1A, it represents a first stress state in which a compressive stress is generated in the feature 104, resulting in a convex curvature of the substrate 100 to compensate for the compressive stress. This curvature can be characterized by the first bend, as shown by H1. The value of H1 can generally represent the height of the center of the substrate 100 minus the height of the outer edge of the substrate 100. In other words, the first bend H1 may represent the value of the vertical segment to the plane 103, where the plane 103 intersects the opposite end of the substrate 100 as shown, and the vertical segment extends through the center of the substrate. The value of H1 accordingly represents the maximum difference between the positions of the features on the first main surface 106 along the Z axis of the Cartesian coordinate system shown. Therefore, the feature at the center of the substrate 100 is positioned in the XY plane relative to the feature at the edge of the substrate, where the height of the XY plane is at the height represented by H1. Therefore, various processing complexity for processing the substrate 100 may occur, including the inability to image features correctly during lithography patterning.

In FIG. 1A, the stress state may represent a plane isotropic stress, in which the resulting substrate bending along the X axis (shown in FIG. 1A) is the same as the substrate bending along the Y axis (not shown). In some embodiments discussed further below, the stress state of FIG. 1A may represent a plane anisotropic stress, where the resulting bending of the substrate along the X axis is different from the bending along the Y axis.

According to an embodiment of the present invention, these types of substrate bending can be solved through a combination of deposition and ion implantation. Referring to FIG. 1B, it shows a subsequent example in which the deposition substance 110 is guided to the second main surface 108 of the substrate 100, which is opposite to the first main surface. In various embodiments, the deposition substance 110 (eg, silicon nitride or other materials) may form a suitable layer in this way. The embodiments are not limited in this context. The resulting layer is shown as stress compensation layer 112 in FIG. 1C.

According to various embodiments, the stress compensation layer 112 may be deposited to an appropriate thickness in order to generate sufficient compensation stress to adjust substrate bending, as shown in FIG. 1A. It is well known that the curvature caused by a deposited layer on a substrate with a given substrate thickness is proportional to the product of the stress in the deposited layer times the thickness in the deposited layer. Therefore, in order to impart a given stress to the stress compensation layer 112, the thickness of the stress compensation layer 112 may be adjusted to produce a target stress-thickness product to produce a target change in substrate bending. According to various embodiments, the stress compensation layer may have a thickness of 100 nm to 500 nm. The embodiments are not limited in this context. According to different embodiments, the deposited stress compensation layer 112 may have neutral stress (zero stress), tensile stress, or compressive stress. Therefore, through any internal stress in the stress compensation layer 112, the stress compensation layer 112 may or may not change the bending of the substrate 100 to assume the value shown as H2.

1D and 1E, it shows a subsequent example of performing an ion implantation procedure (ion implantation procedure) to guide ions 114 into the stress compensation layer 112. In the examples shown in FIGS. 1D and 1E, ions 114 may be directed to the stress compensation layer 112 during blanket exposure, while in other embodiments detailed below, the ion implantation procedure may The first region is exposed to the first implantation process, and the second region of the stress compensation layer 112 is not exposed to the first implantation process.

According to various embodiments, as the implantation of ions 114 progresses, the stress state within the stress compensation layer 112 may change, resulting in a corresponding stress in the stress compensation layer 112, wherein the corresponding stress tends to reduce the substrate bending to the value of H3, This is followed by the value of H4, which is shown as zero and is for illustrative purposes only. In other embodiments, the substrate bending may exhibit a finite value compared to the bending in FIG. 1A, or may exhibit a finite value in the opposite direction.

According to various embodiments, the ion energy of the ions 114 may be adjusted to implant the ions into the appropriate depth of the stress compensation layer 112 in order to cause an appropriate change in stress state. In some examples, ions 114 may be directed into the stress compensation layer 112 at an energy of 100 keV to 1 MeV. The embodiments are not limited in this context.

FIG. 2 depicts the experimental results of stress compensation according to the present embodiment, in which ion implantation into the stress compensation layer has been performed using various cloth materials. The stress compensation layer in this example is a silicon nitride layer, which is deposited on the substrate by low-pressure chemical vapor deposition. There are no patterned structures or other layers on the substrate.

The implantation performed is a blanket implantation into the substrate, which has an initial (original) bend in the X direction and in the Y direction indicating a plane isotropic tensile stress. For each cloth plant material, blanket planting is carried out with an appropriate energy and ion dose to reduce the substrate bending to zero or slightly negative, indicating compressive stress. In each case, the reduction in plane stress is isotropic, meaning that the value of the substrate bending is the same as the change in substrate bending along the X and Y directions. Therefore, according to different embodiments of the present invention, various cloth materials can be used to adjust the plane stress in the stress compensation layer and the resulting substrate bending in a consistent manner.

Referring now to FIG. 3, an anisotropic planar stress is formed in the substrate 150. The substrate 150 may represent a semiconductor wafer. For example, the substrate 150 may be processed in such a manner that semiconductor dies including a plurality of elements are manufactured on or near one main surface of the substrate. For illustrative purposes, a VNAND element 156 is shown, where the VNAND element 156 may be manufactured in a semiconductor wafer that extends beyond the first major surface 158 of the substrate 150. The VNAND element 156 may be formed using the layer stack 160, as in known elements. The layer stack 160 may include dozens of individual layers, resulting in significant layer stress after formation. This layer of stress can be imparted to the substrate 150, causing the substrate to bend, as previously described. It is worth noting that, in the processing stage shown in FIG. 3, vertical slits 162 are formed in the layer stack 160, where the vertical slits can be oriented in a specific direction, as shown parallel to the X axis of the Cartesian coordinate system. Therefore, due to the presence of the vertical slit 162, the stress can be relieved at least partially along the Y direction, rather than along the X direction, where the layer stack 160 can extend in a continuous manner. Therefore, the stress vector 152 representing the stress in the Y direction is shown to be smaller than the stress vector 154 representing the stress in the X direction. The stress anisotropy can cause anisotropic bending in the substrate 150.

According to embodiments of the present invention, techniques and devices are provided to address anisotropic bending in a substrate. Specifically, a stress compensation layer may be formed on the second main surface of the substrate, wherein an ion implantation procedure is performed to induce an anisotropic biaxial stress in the stress compensation layer, thereby compensating the first in the substrate before the ion implantation procedure Anisotropic curvature. For example, the first anisotropic curvature may be the first difference between the first substrate bending in the first direction (X axis) and the second substrate bending in the second direction (Y axis) perpendicular to the first direction To characterize. As a specific example, also referring to FIG. 3, the substrate is bent along the Y axis, which is caused by the formation of the VNAND element 156, which can be 5um, and the substrate is bent along the X axis is 50um, resulting in a difference of 50um-5um or 45um Directional curvature. Therefore, providing an isotropic implantation procedure can reduce changes in plane stress along the X axis and along the X axis in a similar manner, where the overall anisotropy of stress and substrate bending still exists.

According to various embodiments, the anisotropic curvature in the substrate can be reduced by performing a special ion implantation procedure in the stress compensation layer to cause the compensated anisotropic stress. In other words, after the ion implantation procedure, the substrate will exhibit a second anisotropic curvature that is less than the first anisotropic curvature before the ion implantation procedure. This reduction means changing the substrate bending, where the second difference (after implantation) between the third substrate bending in the first direction (X axis) and the fourth substrate bending in the second direction (Y axis) is less than The first difference between substrate bending along the X axis and substrate bending along the Y axis (before implantation).

In view of the above considerations, according to various embodiments, the amount of stress anisotropy caused in the stress compensation layer may be adjusted according to the value of the first anisotropic curvature before ion implantation, and the adjustment is thus caused by the stress compensation layer The amount of anisotropic curvature. Substrates that exhibit a relatively high degree of anisotropic curvature can undergo implantation procedures, causing a relatively high degree of compensated anisotropic curvature caused by the stress compensation layer.

4A-4C, which illustrate the geometry in plan views for different stress compensation operations according to various embodiments of the present invention. As described below, the degree of anisotropic curvature is usually adjusted by creating a planting strip pattern, where the ion dose can vary from 0 to E15/cm ² . The appropriate dose for changing the bending may depend on the ion energy, the thickness of the stress compensation layer, the ion type, and so on. In FIG. 4A, the implantation pattern 200 is shown, which reflects the geometry of the ion implantation procedure performed into the stress compensation layer (not separately shown) provided on the second main surface of the substrate 210. The planting pattern 200 is composed of a plurality of planting strips, shown as a planting strip 202 and a planting strip 204, which alternate with each other. The implantation strip 202 is formed by implanting a certain dose of As (1X (1x)) ions, and the implantation strip 204 is formed by implanting a 10X (10x) dose of As ions. In this example, a total of 9 implants were generated on the second main surface of the substrate 210, where the substrate 210 was a 300 mm Si substrate. When the implanted pattern 200 is applied to the substrate 210 without any patterned features, an anisotropic curvature of 4um is induced on the substrate, which means that the substrate bending along the X axis differs from the substrate bending along the Y axis by 4um . Therefore, the implantation pattern 200 can be suitably applied to a case where a substrate, for example, a substrate having a patterned feature on the first main surface, exhibits a first anisotropic curvature in the range of 4um.

It is worth noting that the implantation pattern 200 can be applied through the oriented substrate to counteract the first anisotropic curvature in the substrate, so that the implantation process tends to reduce substrate bending along the X axis relative to the substrate along the Y axis The difference between bending. For example, the wafer tends to bend more in the direction of the implantation strip. Therefore, the degree of curvature in the X direction of FIG. 4A is greater than that in the Y direction by 4 um. Therefore, it is possible to deal with substrate bending having a larger direction in the X direction than in the Y direction by aligning the planting strips of FIG. 4A to produce a compensated anisotropic bending to reduce the difference in bending in the substrate.

Therefore, if the initial substrate bending is 20 um along the X-axis and 16 um along the Y-axis, the substrate 210 may be oriented such that the implantation pattern 200 reduces the flexion along the X-axis by 20 um and decreases the 16-axis along the Y-axis Bending, so that the overall isotropic plane stress along the X-axis direction and along the Y-axis direction is zero

In FIG. 4B, the implantation pattern 220 is shown, which reflects the geometry of the ion implantation procedure performed into the stress compensation layer (not separately shown) provided on the second main surface of the substrate 210. The planting pattern 220 is composed of a plurality of planting strips, shown as a center planting strip 212 and two planting strips, namely, planting strips 214, which alternate with each other. The central implant strip 212 is formed by implanting As with a 1X (1 times) dose of As, and the implant strip 214 is formed by implanting As with a 10X (10 times) dose of As ions. In this example, a total of 3 implants were generated on the second main surface of the substrate 210, where the substrate 210 was a 300 mm Si substrate. When the implanted pattern 220 is applied to the substrate 210 without any patterned features, an anisotropic curvature of 12um is induced on the substrate. Therefore, the implantation pattern 220 can be suitably applied to a case where a substrate, such as a substrate having patterned features on the first main surface, exhibits a first anisotropic curvature in the range of 12um.

It is worth noting that the implantation pattern 220 can be applied through the oriented substrate to counteract the first anisotropic curvature in the substrate, so that the implantation process tends to reduce substrate bending along the X axis relative to the substrate along the Y axis Bending difference. Therefore, if the initial substrate bending is 20 um along the X axis and 8 um along the Y axis, the substrate 210 may be oriented such that the implant pattern 220 reduces 20 um along the X axis and reduces 8 um along the Y axis. The bending results in zero stress along the X-axis and Y-axis.

In FIG. 4C, the implantation pattern 230 is shown, which reflects the geometry of the ion implantation procedure performed into the stress compensation layer (not separately shown) provided on the second main surface of the substrate 210. The planting pattern 230 is composed of a plurality of planting strips, of which the center strip 222 is unplanted and the two sides are planting strips 2, which alternate with each other. The implantation strip 214 is formed by implanting a 10X (10 times) dose of As (the same as in FIGS. 4B and 4A) As ions. In this example, a total of 3 implants are produced across the second main surface of the substrate 210, where the substrate 210 is a 300 mm Si substrate. When the implanted pattern 230 is applied to the substrate 210 without any patterned features, an anisotropic curvature of 32um is induced on the substrate. Therefore, the implantation pattern 230 can be suitably applied to a case where a substrate, such as a substrate having a patterned feature on the first main surface, exhibits a first anisotropic curvature in the range of 32um. Of course, in this and other examples, the implantation pattern may be applied to partially compensate for the initial anisotropic curvature, where the implantation pattern reduces the anisotropic curvature while not eliminating the anisotropic curvature.

It is worth noting that the implantation pattern 230 can be applied through the oriented substrate to counteract the first anisotropic curvature in the substrate, so that the implantation process tends to reduce the bending of the substrate along the X axis relative to the substrate along the Y axis The difference between bending. Therefore, if the initial substrate bending is a bending along the X axis of 40 um and a bending along the Y axis of 8 um, the substrate 210 may be oriented such that the placement pattern 230 reduces the bending along the X axis by 40 um, and reduces the along 8 um The bending of the Y-axis causes the overall isotropic plane stress along the X-axis and along the Y-axis to be zero.

5A-5C depict the substrate geometry during various operations in the stress compensation procedure according to various embodiments of the invention. The sequence shown shows the initial anisotropic curvature in the substrate (for example, the curvature caused by the anisotropic stress in the patterned structure on the first major surface of the substrate) and the Compensate the geometric relationship between programs. In FIG. 5A, a substrate 250 is shown in which an anisotropic tensile stress is generated on the first main surface 252, for example, is manufactured through a VNAND device, or any other anisotropic curvature source. The anisotropic curvature is expressed as the curvature of the flat substrate along the Y axis and the concave substrate along the X axis, as shown in the figure, which represents the unidirectional tensile stress in the layer on the first major surface 252.

In FIG. 5B, a first operation is shown in which a stress compensation layer (not separately shown) is deposited on the second main surface 254. After the stress compensation layer is deposited, the stress compensation layer may generate isotropic stress on the second major surface 254. In some examples, the CVD layer deposited as a stress compensation layer may exhibit tensile stress. Because the tensile stress is deposited on the second major surface 254, the effect will be to produce a curvature as shown, where the substrate 250 along the X axis will end to have a curvature that is smaller than the initial curvature in FIG. 5A, because in the second The compensated tensile stress of the stress compensation layer on the main surface 254 is opposite to the tensile stress on the first main surface 252. In FIG. 5A, the substrate 250 is shown as being flat along the X axis, and in some embodiments, the stress after the deposition of the stress compensation layer can still provide curvature along the X axis of the substrate, although it is removed from FIG. 5A The curvature of is reduced. In FIG. 5B, the compensated tensile stress formed on the second main surface 254 may bend the substrate 250 along the Y axis, as shown.

Referring to FIG. 5C, which shows a plan view of the substrate 250, the implantation pattern 230 is applied in the form of a strip and parallel to the X axis, as shown. It is worth noting that the ion implantation substrate 300 may tend to release or reduce tensile stress (see FIG. 2). Since the implantation pattern 230 affects the stress and the curvature of the substrate in an anisotropic manner, the orientation of the implantation pattern 230 with stripes in a given direction will have an anisotropic effect on the curvature or stress in the substrate. In this example, the tensile stress decreases along the Y axis, which is perpendicular to the direction of the implantation strip, resulting in a flatter profile of the substrate 250 along the Y axis without affecting the profile along the X axis. It is worth noting that the processes outlined in FIGS. 5A-5C are schematic, and the amount of anisotropic curvature in the substrate to be compensated can vary, and can be resolved by different implant patterns, as described above.

6A depicts a schematic top view of an ion implantation system for generating anisotropic stress control according to an embodiment of the present invention. The ion implantation system, called ion implanter 300, represents a processing chamber that contains, among other components, an ion source 304 for generating an ion beam 308 and a series of beamline components. The ion source 304 may include a chamber for receiving gas flow and generating ions. The ion source 304 may also include a power source and an extraction electrode assembly (not shown) provided near the chamber. The beamline components may include, for example, an analyzer magnet 320, a mass resolution slit (MRS) 324, a turning/focusing component 326, and an end station 330 including a substrate support 131.

The ion implanter 300 also includes a beam scanner 336 positioned along the beam line 338 between the MRS 324 and the end station 330. The beam scanner 336 may be arranged to receive the ion beam 308 as a spot beam and scan the ion beam 308 in the fast scanning direction, for example parallel to the direction of the X axis in the Cartesian coordinate system shown. It is worth noting that the substrate 332 can be scanned along the Y axis, so when the ion beam 308 is scanned back and forth along the X axis at the same time, a given ion treatment can be applied to a given area of the substrate 332. The ion implanter 300 may have other components, such as collimators known in the art (not shown for clarity) to guide the ions of the ion beam 308 to the substrate along a series of mutually parallel trajectories after scanning 332, as proposed in Figure 5A. In various embodiments, the ion beam can be scanned at frequencies of a few Hz, 10 Hz, 100 Hz, up to several thousand Hz or higher. For example, the beam scanner 336 may scan the ion beam 308 using magnetic or electrostatic scanning elements, as known in the art.

By rapidly scanning the ion beam 308 in the fast scanning direction, for example, moving back and forth along the X axis, the ion beam 308 configured as a spot beam can deliver a target ion dose of uniform density on the substrate 332. According to various embodiments, the ion beam 308 may be controlled (in response to user input) to generate a target implant pattern through the combination of the scanning substrate 332 and the scanning ion beam 308 (see FIGS. 4A-4C).

For example, the ion implanter 300 may also include a controller 340 that is coupled to the beam scanner 336 to coordinate the operation of the beam scanner 136 and the substrate stage 331. As further shown in FIG. 5A, the ion implanter 300 may include a user interface 342, which is also coupled to the controller 340. The user interface 342 may be embodied as a display, and may include user selection elements, including touch screens, displayed menus, buttons, knobs, and other elements known in the art. According to various embodiments, the user interface 342 may send an instruction to the controller 340 according to user input to generate an appropriate placement pattern for the substrate 332.

As further shown in FIG. 6B, the controller 340 may include a processor 352, such as a microprocessor of a known type, a dedicated processor chip, a general-purpose processor chip, or the like. The controller 340 may also include a memory or memory unit 354 coupled to the processor 352, where the memory unit 354 includes a scan routine 356. The scanning routine 356 may be operated on the processor 352 to manage the scanning of the ion beam 308 and the substrate 332 as described below. The memory unit 354 may include an article. In one embodiment, the memory unit 354 may include any non-transitory computer-readable medium or machine-readable medium, such as optical, magnetic, or semiconductor storage. The storage medium may store various types of computer-executable instructions to implement one or more logic flows described herein. Examples of computer-readable or machine-readable storage media may include any tangible media capable of storing electronic data, including volatile or non-volatile memory, removable or non-removable memory, erasable or non-removable Erase memory, write or rewrite memory, etc. Examples of computer executable instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, object-oriented code, visual code, and so on. The embodiments are not limited in this context.

In certain embodiments, the scan routine 356 may include an implantation pattern processor 358 and a scan control processor 360. The implant pattern processor 358 may receive a set of substrate stress information, for example, from the user interface 342, which indicates the stress state in the substrate 332. The substrate stress information may include substrate thickness, stress compensation layer thickness, anisotropic curvature of the substrate, and so on. The implantation pattern processor 358 may use the substrate stress information to calculate appropriate implantation pattern information to counteract the anisotropic curvature of the substrate. The implantation pattern information may include ion dose, ion species, and implant strip size, as discussed generally above. In various embodiments, a series of implant patterns can be stored in the database 362, where different implant patterns can be associated with different degrees of anisotropic curvature in the substrate. The scan control processor 360 can control the scanning of the substrate 332 and the scanning of the ion beam 308 to implement the implantation pattern in the substrate 332. Therefore, in various embodiments, processing the substrate using the implant pattern to generate anisotropic stress in the stress control layer may be automated, or partially automated.

Referring now to FIG. 7, a process flow 700 according to some embodiments of the invention is shown.

At block 702, an operation of providing a substrate is performed. Generally, the substrate may have an anisotropic stress within the first main surface or within features provided on the first main surface, thereby causing an anisotropic curvature of the substrate. In certain embodiments, the substrate may be a patterned substrate, where the patterning includes any number of layers, elements, or structures on the first major surface. The patterned substrate may be characterized by a second main surface opposite to the first main surface.

At block 704, a stress compensation layer is deposited on the second major surface. In some non-limiting embodiments, the stress compensation layer may have a thickness between 100 nm and 500 nm.

At block 706, an implantation procedure is determined based on the anisotropic curvature of the substrate. The implantation procedure may include implantation patterns, including ion energy, ion type, ion dose, etc. The implantation program can be calculated to compensate for the anisotropic curvature of the substrate.

At block 708, the stress compensation layer is exposed to an ion implantation procedure, wherein the implantation procedure includes scanning a first ion beam relative to the substrate to implant a first dose of ions in the first region of the stress compensation layer, wherein the stress compensation The second area of the layer is not exposed to the first dose of ions. In some embodiments, the first area may consist of at least one bar, and the second area may similarly consist of one or more bars, where the total number of bars is at least three. In some embodiments, the second area may be unplanted, while in other embodiments, the second area may be exposed to a second dose of ions different from the first dose of ions, and may be exposed to different cloth plants Quality, different planting energy, or a combination of the above.

The advantages provided by this embodiment are various. As a first advantage, this embodiment provides the ability to dynamically adjust the curvature of the substrate during processing. In other words, based on the undesired substrate curvature caused during the device manufacturing stage (eg, during the formation of the VNAND device), the undesired substrate curvature can be reduced by direct combination of the deposition of the stress compensation layer and subsequent ion implantation. This intervention allows subsequent elements to be performed with higher precision, such as a lithography step that requires a relatively flat substrate later. As a second advantage, embodiments of the present invention use a novel patterned implantation procedure to help reduce or eliminate anisotropic stress, thereby allowing anisotropic substrate curvature to be reduced or eliminated.

The invention is not limited to the scope of the specific embodiments described herein. In fact, in addition to those described herein, other various embodiments and modifications of the present invention will be apparent to those skilled in the art from the foregoing description and drawings. Therefore, these other embodiments and modifications are intended to fall within the scope of the present invention. Furthermore, the present invention has been described herein in the context of a specific implementation in a specific environment for a specific purpose, however, those of ordinary skill in the art will recognize that the usefulness is not limited to this, and the present invention may advantageously be in any number of Implemented in an environment and used for any purpose Therefore, in consideration of the full scope and spirit of the present invention as described herein, the scope of patent applications set forth below will be explained.

100: substrate 106: First main surface 104: Features H1: curved 103: Flat 110: Sediment 108: Second main surface 112: Stress compensation layer H2: curved 114: ion H3: curved H4: curved 150: substrate 156: VNAND components 158: First main surface 160: layer stack 162: Vertical slit 152: Stress vector 154: Stress vector 200: planting patterns 210: substrate 202: planting strip 204: planting strip 212: Center planting strip 214: planting strip 230: planting patterns 222: Center bar 214: planting strip 250: substrate 252: First main surface 254: Second main surface 300: ion implantation substrate 308: ion beam 304: ion source 320: Analyzer magnet 324: Mass Resolution Slot (MRS) 326: Steering/focusing component 131: substrate support 330: end station 338: Harness 336: Beam scanner 340: Controller 336: Beam scanner 331: substrate table 342: User interface 352: processor 354: Memory unit 356: Scanning routine 358: planting pattern processor 360: Scanning control processor 362: Database 700: Process flow 702: Box 704: Box 706: Box 708: box

1A-1F depict side cross-sectional views of a substrate at various stages of a stress compensation operation according to an embodiment of the present invention;

FIG. 2 depicts the experimental results of stress compensation according to this embodiment;

Fig. 3 depicts a case where anisotropic stress is formed on the substrate;

4A-4C depict the geometry for different stress compensation operations according to various embodiments of the invention;

5A-5C depict the substrate geometry during various operations in the stress compensation process according to various embodiments of the invention;

6A-6B depict different representations of ion implanters according to various embodiments of the invention; and

FIG. 7 depicts an exemplary processing flow.

Domestic storage information (please note in order of storage institution, date, number) no

Overseas hosting information (please note in order of hosting country, institution, date, number) no

100: substrate

106: First main surface

104: Features

112: Stress compensation layer

114: ion

H3: curved

Claims (15)

A method, including the following steps: Providing a substrate including a first main surface and a second main surface opposite to the first main surface, the second main surface including a stress compensation layer; and To guide ions to the stress compensation layer in an ion implantation procedure, the ion implantation procedure includes the following steps: Exposing a first area of the stress compensation layer to a first implantation process, Wherein, a second area of the stress compensation layer is not exposed to the first implantation process. The method according to claim 1, wherein the substrate is a patterned substrate, the patterned substrate further includes a feature component disposed on the first major surface, the feature component generating a first on the patterned substrate Stress state. The first stress state includes an anisotropic stress along the first major surface. The method according to claim 1, wherein after the ion implantation procedure, the stress compensation layer contains an anisotropic biaxial stress in the second main surface. The method according to claim 1, wherein before the ion implantation process, the substrate exhibits a first anisotropic curvature along the first major surface, the first anisotropic curvature includes along a first A first difference between a first substrate bend in one direction and a second substrate bend along a second direction perpendicular to the first direction, and After the ion implantation process, the substrate exhibits a second anisotropic curvature, the second anisotropic curvature includes a third substrate bending along the first direction and a fourth along the second direction A second difference between the bending of the substrate, the second anisotropic curvature is smaller than the first anisotropic curvature. The method according to claim 4, wherein the first substrate is curved larger than the second substrate, and wherein the first area includes a plurality of planting strips oriented in the second direction. The method according to claim 4, wherein the ion implantation process generates an implantation pattern in the stress compensation layer, the implantation pattern includes a center strip oriented along the second direction, the center strip is not Being planted, and wherein the side of the center strip is a first planting strip on a first side, and a second planting strip on a second side. The method of claim 1, comprising exposing the second region of the stress compensation layer to a second implantation process different from the first implantation process. The method according to claim 1, wherein a thickness of the stress compensation layer is 100 nm to 500 nm. The method according to claim 1, wherein the first implantation process includes directing the ions to the stress compensation layer with an energy of 100 keV to 1 MeV. A method, including the following steps: A patterned substrate is provided. The patterned substrate includes a first main surface and a second main surface opposite to the first main surface. The patterned substrate further includes: A feature component disposed on the first main surface, the feature component generating a first stress state on the patterned substrate, the first stress state including an anisotropic stress in the first main surface; Deposit a stress compensation layer on the second major surface; and Exposing the stress compensation layer to an ion implantation procedure, wherein the ion implantation procedure includes: In a first implantation procedure, a first ion beam is scanned relative to the patterned substrate to implant a first dose of ions in a first area of the stress compensation layer, A second area of the stress compensation layer is not exposed to the first dose of ions. The method according to claim 10, wherein, before the ion implantation process, the substrate exhibits a first anisotropic curvature along the first major surface, the first anisotropic curvature includes along a first A first difference between a first substrate bend in one direction and a second substrate bend along a second direction perpendicular to the first direction, and Wherein the patterned substrate exhibits a second anisotropic curvature after the ion implantation process, the second anisotropic curvature includes a third substrate bending along the first direction and a first along the second direction A second difference between the bending of the four substrates, the second anisotropic curvature is smaller than the first anisotropic curvature. The method according to claim 11, wherein the ion implantation process generates an implantation pattern in the stress compensation layer, the implantation pattern includes a central strip oriented along the second direction, the central strip is not deployed Planted, and wherein the side of the center strip is a first cloth planting strip on a first side, and a second cloth planting strip on a second side. The method according to claim 10, comprising the step of: exposing the second region of the stress compensation layer to a second implantation process different from the first implantation process. The method according to claim 10, wherein the stress compensation layer includes a thickness of 100 nm to 500 nm, and wherein the first implantation process includes guiding the ions to the stress compensation layer with an energy of 100 keV to 1 MeV. A device for stress control of a substrate includes: A beam scanner for scanning an ion beam relative to a substrate, the substrate including a stress control layer; A user interface, coupled to the beam scanner; A controller, coupled to the beam scanner and the user interface, the controller includes: A processor; and A memory unit, coupled to the processor, includes a scanning routine that operates on the processor to receive substrate stress information from the user interface and generate an implant pattern to control the beam In the scanner, the placement pattern generates an anisotropic stress in the stress control layer.

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